A lot of circuits rely on a reference voltage to provide a reference voltage level for various applications. For example, an Analog-to-digital converter (ADC) or a Digital-to-analog converter (DAC) circuit may need a reference voltage to be a Least significant bit (LSB) level, and a regulator may need a reference voltage to be a reference output voltage level.
Generally, the reference voltage is generated by a reference voltage generator, and a reference voltage buffer circuit is commonly set between the reference voltage generator and the concerned circuits to ensure the ability of the reference voltage. However, the reference voltage provided by the reference voltage circuit may be affected by noise and/or interference such that sometimes the concerned circuits cannot obtain an enough clean reference voltage (e.g., a stable and accurate reference voltage) to perform the desired applications. In view of this, it is important to provide a solution to improve the problems in the art.